public async Task SetPositionBalanceTest()
{
_handler.Expect(HttpMethod.Post, $"{BaseUri}sandbox/positions/balance")
.WithQueryString("brokerAccountId", BrokerAccountId)
.WithJsonContentFromFile("set-position-balance-request")
.RespondJsonFromFile("ok");
await _context.SetPositionBalanceAsync("BBG000CL9VN6", 100.7m, BrokerAccountId);
}